JP2007316527A - Projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: In a conventional screen holding structure, when an external force is applied to a housing and deformed, the housing is not sufficiently restored due to a frictional force between a pressing member and a screen even after the external force is unloaded. . For this reason, there is a problem that the relative position between the optical engine and the screen remains, and image distortion occurs.
SOLUTION: Press members 201 and 203 that press and hold the peripheral side of the screen 20 in the screen surface direction, and the pressing force of the upper side of the screen 20 by the pressing member 201 is smaller than the pressing force of the lower side by the pressing member 203. It was configured as follows.
[Selection] Figure 2

Description

  The present invention relates to a screen holding structure of a rear projection type projection television.

  In the conventional screen holding structure of the projection apparatus, the screen is sandwiched between pressing members, held by an attachment member, and attached to a housing. The four sides of the screen have the same configuration. (For example, refer to Patent Document 1.)

Japanese Laid-Open Patent Publication No. 2004-212953 (Page 10, Fig. 7)

  For example, FIG. 12 is a structural analysis diagram of the housing 3. It is assumed that an external force acts on the upper corner of the housing 3 when moving or cleaning the room even when the projection apparatus is installed or after it is installed. For example, the force Pz (−) on the upper right and the force Pz (+) on the upper left may act to twist the housing 3. In this case, when the frame 10 holding the periphery of the screen (not shown) is viewed from the Z direction in the drawing (that is, when viewed from the front of the screen), the upper side moves in the direction of arrow D as shown in FIG. Thus, it is known from the structural analysis and the actual measurement that the whole is distorted into a parallelogram. This will be described with reference to FIG. FIG. 14A shows a state before the deformation, and the screen 20 has a peripheral direction around the pressing member 201 (upper side), 202 (right side), 203 (lower side), and 204 (left side). And is held and positioned by the frame body 10. FIG. 14B shows the state after deformation. Although the frame 10 is deformed into a parallelogram by moving the upper side in the direction of arrow D, the screen 20 is generally formed of a rectangular acrylic plate material and cannot be transformed into a parallelogram in the plane. Keep the rectangle. That is, a deviation occurs between the screen 20 and the pressing members 201, 202, 203, and 204. Next, considering the case where the external force is unloaded, the restoring force due to the rigidity of the casing 3 acts and the casing 3 tries to restore the original shape. At this time, the screen 20 and the pressing member 201 are restored. , 202, 203, and 204, and is not completely restored. Due to this residual deformation, there is a problem that the relative position between the optical engine 6 and the screen 20 remains displaced, and image distortion occurs.

  The projection device according to the present invention is made to solve the above-described problems, and includes a screen, an optical engine that projects an image from the back onto the screen, the screen, and the optical engine. A housing mounted inside, a frame attached to the housing to hold a peripheral side of the screen, an upper side pressing member that presses and holds the upper side of the screen in the screen surface direction to the frame, The frame body includes a lower side pressing member that presses and holds the lower side of the screen in the screen surface direction, and the pressing force of the upper side pressing member is smaller than the pressing force of the lower side pressing member.

  In the projection device according to the present invention, the pressing force of the upper side pressing member that presses and holds the upper side of the screen is made smaller than the pressing force of the lower side pressing member that presses and holds the lower side, and the frictional force between the upper side of the screen and the pressing member is reduced. Even if the housing is deformed by the action of an external force, the projection device can be easily restored to its original shape when the external force is unloaded, thereby realizing a projection device with less image displacement and distortion. is there.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a projection apparatus according to Embodiment 1 of the present invention. In the figure, reference numeral 10 denotes a frame body that holds a screen 20 and is attached to a housing 3. 6 is an optical engine that is mounted inside the housing 3 and enlarges and projects an image. The image 7 projected from the projection lens 8 is reflected by a mirror 4 attached to the back surface of the housing 3, and Projected onto the screen 20 from the back.

  Next, the detail of the fixing part to the frame 10 of the screen 20 is demonstrated based on FIG. FIG. 2A shows a detailed cross-sectional view of the portion X (upper side of the screen) in FIG. 1, and FIG. 2B shows a detailed cross-sectional view of the Y portion (lower side of the screen) in FIG. In FIG. 2A, the screen 20 is mounted on the inner side (right side in the figure) of the frame body 10, and is pressed and fixed by a pressing member 201 formed of an elastic member and a fixing member 101 fixed to the frame body 10 by screws 50. Has been. In FIG. 2B, the screen 20 is mounted on the inner side (right side in the figure) of the frame body 10, and a pressing member 203 formed of an elastic member having a different elastic modulus from the pressing member 201 and a screw 50 are used to form the frame body 10. It is pressed and fixed by a fixing member 103 fixed to the head. It is to be noted that the screen 20 has its own weight and is near the lower end in a portion different from that shown in FIG.

  Next, the elastic modulus of the pressing member will be described with reference to FIG. In the figure, the horizontal axis indicates the deflection (here, the amount of compressive deformation), and the vertical axis indicates the pressing force. The inclinations of the lines A and B indicate the elastic moduli of the pressing members 201 and 203, respectively. In FIG. 2, the pressing members 201 and 203 are both attached so as to generate the same amount of deflection (D in this case), and the pressing forces generated at this time are P1 and P2, respectively, from FIG. The relation of P1 <P2 is established, and the pressing force of the pressing member 201 is set smaller than the pressing force of the pressing member 203. Of course, it goes without saying that the pressing force of the pressing member 203 is set to be equal to or higher than the pressing force that can stably bring the upper side of the screen 20 into close contact with the frame 10.

  Next, the operation will be described. As described above, when installing the projection apparatus, or during movement after installation or indoor cleaning, an external force is applied to the upper corner of the housing 3, for example, a force Pz (−) on the upper right as shown in FIG. A force Pz (+) may act on the housing 3 to twist the housing 3 in some cases. In this case, the frame 10 that holds the peripheral side of the screen 20 is such that the upper side moves in the direction of arrow D as shown in FIG. The whole is distorted into a parallelogram.

This will be further described with reference to FIG. FIG. 14A shows a state before deformation, in which the screen 20 is held on the frame 10, and the pressing members 201 (upper side), 202 (right side), 203 (lower side), and 204 (left side) are in the plane direction (that is, The screen 20 is pressed and positioned toward the viewer side. FIG. 14B shows the state after deformation. The frame 10 is deformed into a parallelogram by moving the upper side in the direction of the arrow D. However, the screen 20 is generally formed of an acrylic plate and cannot be transformed into a parallelogram in the plane. Keeps the rectangle. That is, a deviation occurs between the screen 20 and the pressing members 201, 202, 203, and 204. At this time, the screen 20 receives its own weight and the lower end is in contact with the frame body 10, and the frictional force of the contact portion is applied in addition to the pressing force of the pressing member 203 at the lower end. Without moving with respect to the frame body 10, the upper side is displaced from the frame body 10 in the arrow D direction.

  Next, consider the case where the external force is unloaded. The restoring force due to the rigidity of the casing 3 acts, and the casing 3 and the frame body 10 try to restore to the original shape. At this time, since the pressing member 201 on the upper side is set to have a smaller pressing force than the pressing member 203 on the lower side, the frictional force is small, and even if the upper side is largely deviated, the housing 3 is the original. There is no hindrance to restoring the shape. Therefore, the residual deformation of the housing 3 can be reduced, the shift of the relative position between the optical engine 6 and the screen 20 can be suppressed, and the image distortion of the projection apparatus can be suppressed.

Embodiment 2. FIG.
In the first embodiment, the elastic force of the pressing member 201 on the upper side of the screen 20 is made smaller than the elastic force of the pressing member 203 on the lower side to reduce the pressing force generated by the same deflection. The elastic force may be the same, and the pressing force may be different by changing the initial thickness (the dimension in the screen surface direction when no pressure is applied) to provide a difference in the amount of deflection.

  In FIG. 4, reference numeral 211 denotes an upper side pressing member having a thickness L <b> 1, and after being fixed by the fixing member 101, is compressed and held to a thickness S <b> 1. In FIG. 5, reference numeral 213 denotes a lower side pressing member having a thickness of L <b> 2, and after being fixed by the fixing member 103, is compressed and held to a thickness of S <b> 1. Since the initial thickness is formed such that L1 <L2, the pressing force after fixing becomes upper side <lower side. Since the details of the operation are the same as those in the first embodiment, description thereof is omitted.

Embodiment 3 FIG.
In the second embodiment, the pressing force is changed by changing the initial thickness of the pressing member 211 on the upper side and the pressing member 213 on the lower side. However, as the same initial thickness, the thickness at the time of pressing is changed to reduce the compression amount. It is good also as a structure from which pressing force differs by providing a difference.

In FIG. 6, the screen back surface 20a and the fixing member mounting surface 10a are formed with a step size of N1. Reference numeral 221 denotes an upper side pressing member formed to have a thickness of L2, and after being fixed by the fixing member 101, is compressed and held to a thickness of S1. In FIG. 7, the screen back surface 20a and the fixing member mounting surface 10a are formed with a step size of N2. 223 is a lower side pressing member having the same thickness L2, and after being fixed by the fixing member 103, it is compressed and held to a thickness of S2. Since N1> N2, it is S1> S2, and the pressing force after fixing is the upper side <the lower side. Since the details of the operation are the same as those in the first embodiment, description thereof is omitted.

Embodiment 4 FIG.
In the third embodiment, the pressing force is different by changing the compression amount of the pressing member 221 on the upper side and the pressing member 223 on the lower side. However, the compression amount is the same, and the initial cross-sectional area (when no pressure is received) It is good also as a structure from which pressing force differs by providing a difference in (cross-sectional area).

  In FIG. 8, reference numeral 231 denotes an upper side pressing member formed with an initial thickness of L2 and a width of M1, and has an initial cross-sectional area of L2 × M1, and after being fixed by the fixing member 101, has a thickness of S1. Compressed and held. In FIG. 9, reference numeral 233 denotes a lower side pressing member having an initial thickness of L2 and a width of M2, which has an initial cross-sectional area of L2 × M2, and after being fixed by the fixing member 103, is also a thickness of S1. Compressed and held. Since the width is formed as M1 <M2, the initial cross-sectional areas of the upper and lower pressing members are (L2 × M1) <(L2 × M2), and if the compression amount is the same, the pressing force after fixing is Upper side <lower side. Since the details of the operation are the same as those in the first embodiment, description thereof is omitted.

Embodiment 5 FIG.
In the first to fourth embodiments, the screen 20 is mounted on the inner side (right side in the figure) of the frame body 10, the pressing members 201 to 204, 211, 213, 221, 223, 231, and 233 are sandwiched between the frame bodies by screws 50. 10, the frame 1001 has a U-shaped cross section, and the elastic piece 2001 is placed in the gap S <b> 3 on the inner surface as shown in FIG. 10. It is good also as a structure which arrange | positions and gives the pressing force to the screen 20. FIG. For example, as shown in FIG. 11, the lower side portion is set to have a U-shaped width smaller than that of the upper side, and an elastic piece 2003 is provided in a gap S 1 to apply a pressing force to the screen 20. Here, when the elastic pieces 2001 and 2003 are configured with the same elastic modulus, by setting the gap width to S3> S4, the pressing force becomes the upper side <lower side. Since the details of the operation are the same as those in the first embodiment, description thereof is omitted.

  As an application example of the present invention, it can be applied to a large-screen projection television apparatus for home use or business use.

It is a block diagram of the projection apparatus of Embodiment 1 of this invention. It is a block diagram of Embodiment 1 of this invention. It is explanatory drawing of Embodiment 1 of this invention. It is a block diagram of Embodiment 2 of this invention. It is a block diagram of Embodiment 2 of this invention. It is a block diagram of Embodiment 3 of this invention. It is a block diagram of Embodiment 3 of this invention. It is a block diagram of Embodiment 4 of this invention. It is a block diagram of Embodiment 4 of this invention. It is a block diagram of Embodiment 5 of this invention. It is a block diagram of Embodiment 5 of this invention. It is modification explanatory drawing of a general projection apparatus. It is modification explanatory drawing of a general projection apparatus. It is modification explanatory drawing of a general projection apparatus.

Explanation of symbols

10 frame body, 20 screen, 3 housing, 201, 202, 203, 204, 211, 213, 221, 223, 231, 233 pressing member, 101, 103 fixing member.

Claims (5)

In a projection apparatus comprising a screen, an optical engine for projecting an image from the back onto the screen, and a housing for holding the screen and mounting the optical engine therein,
A frame attached to the housing to hold a peripheral edge of the screen;
An upper side pressing member that presses and holds the upper side of the screen in the screen surface direction to the frame;
A lower side pressing member that presses and holds the lower side of the screen in the screen surface direction on the frame,
The projection apparatus according to claim 1, wherein a pressing force of the upper side pressing member is smaller than a pressing force of the lower side pressing member.   The projection device according to claim 1, wherein an elastic modulus of the upper side pressing member is smaller than an elastic modulus of the lower side pressing member.   The projection apparatus according to claim 1, wherein an initial thickness of the upper side pressing member is smaller than an initial thickness of the lower side pressing member.   The projection apparatus according to claim 1, wherein a compression amount of the upper side pressing member is smaller than a compression amount of the lower side pressing member. The projection device according to claim 1, wherein an initial sectional area of the upper side pressing member is smaller than an initial sectional area of the lower side pressing member.

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